Nutritional products for athletes typically address a single need of the athlete. Most products focus on supply of either energy (carbohydrate and electrolyte based products) or protein. When consumed within an hour after exercise, carbohydrates help to quickly rebuild energy stores through restoring muscle and liver glycogen. Protein and amino acid based products can help speed absorption of carbohydrates and provide building blocks to repair muscles.
None of these types of products can address the initiation of tissue recovery, which is mediated by the immune system. In addition, there is a frequently noted correlation between prolonged heavy exercise and upper respiratory tract infection (URTI). While the causal pathways are not certain, it is recognized that exercise has multiple effects on the immune system which might explain these observations.
It is widely accepted that both acute and chronic exercise alter the number and function of circulating cells of the innate immune system (e.g., neutrophils, monocytes and natural killer (NK) cells). Similarly, it is agreed that a lymphocytosis is observed during and immediately after exercise, proportional to exercise intensity and duration, with the number of cells (T cells and to a lesser extent B cells) falling below pre-exercise levels during the early stages of recovery, before returning to resting values normally within 24 hours. Finally, a consensus exists that reduced levels of secretory immunoglobulin A (SIgA) are associated with increased risk for URTI during heavy training as the production of SIgA is the major effector function of the mucosal immune system providing the ‘first line of defense’ against pathogens. Thus, there is an ongoing need to manage and reduce the negative effects of exercise on the immune system to keep athletes healthy and performing at their highest levels.
Further, independent of immune system effects, there is a need to improve performance levels of athletes for athletes of all calibers.